Seal placement tool



Dec. 1966 P. J. JESSEN SEAL PLACEMENT TOOL Filed Jan. 5, 1965 554 553 asM United States Patent 3,289,502 SEAL PLACEMENT TOOL Paul .I. lessen,Kenosha, Wis., assignor to American Motors Corporation, Kenosha, Wis., acorporation of Maryland Filed .Ian. 5, 1965, Ser. No. 423,555 Claims.(Cl. 8.1-8.1)

The invention relates to a seal placement tool and has particularreference to a tool for installing a seal in place on a valve stem withreference to the valve stem guide.

In an overhead valve type of internal combustion engine, the valve stemsproject through the cylinder head casting for engagement by a suitablerocker arm and valve guides in the form of elongated sleeves are mountedin the cylinder head casting for reciprocably receiving the valve stems.A seal assembly is mounted at the upper end of each valve guide forencircling the valve stem to prevent escape of lubricating oil at theupper end of the valve guide.

In prior art tools of the type for installing the seal assembly onto thevalve stem and guide, the factor of human error was inadequatelyconsidered and consequently higher costs were incurred due to sealspoilage and due to the excessive time required in placing each seal. Aparticular problem involved the tendency of the tool to aberrate fromtrue axial alignment relative to the valve stem thereby causingdislodgement of the seal insert from the main seal body or causing someother form of damage.

The principal object is to provide a seal placement tool whicheliminates the disadvantages of prior art tools, thereby reducingspoilage to a minimum while permitting rapid placement of each seal soas to keep labor costs at a minimum.

A specific object is to provide a seal placement tool which assuresconcentricity and accurate axial alignment of the seal assembly withreference to the valve stem and valve stem guide prior to and duringplacement thereof.

Other objects and advantages of the invention will be apparent from theensuing specification and appended drawing in which:

FIGURE 1 is a fragmentary side elevational view of the tool in retractedposition.

FIGURE 2 is a view similar to FIGURE 1 but including the valve stem,guide and cylinder head casting and showing the tool in the position inwhich the seal has been completely installed on the valve stem withreference to the valve stem guide.

FIGURE 3 is an enlarged sectional detail view of the seal as it isinitially started on the valve stem prior to use of the seal placementtool.

Referring to FIGURE 2, I have shown a portion of a cylinder head castingA in which a valve stem guide B is mounted. The valve stem C isreciprocably mounted with reference to the guide and the seal assembly Dencircles the valve stem and the upper end of the valve stem guide forpreventing the escape of lubricating oil as the valve stem reciprocateswithin the guide.

The upper surface of the cylinder head casting in the area adjacent toeach valve stem guide is machined flat and an upwardly projectingshoulder 11 has a cylindrical exterior surface 12 which is at rightangles to the casting surface 10. The cylindrical shoulder serves as alocating surface for use with the seal placement tool, which isidentified generally by the letter E. Each valve stem guide is providednear its upper end with an annular groove 13 for anchoring the annularflange 14 of the seal with reference to the valve stem guide, and anannular split type locking ring 15 provides sufficient tension foranchoring the seal flange with reference to th guide.

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Referring to FIGURE 1, the seal placement tool includes an outer sleeve17 having a cylindrical internal bore 18 terminating With thediametrically reduced bore 20 which, of course, is concentric withcylindrical internal bore 18 and which results in the formation of theannular shoulder 19. A plunger 21 is provided with bore 24 whichcommunicates with diametrically enlarged first counterbore 23 which, inturn, communicates with a further diametrically enlarged secondcounterbore 22. Bore 24 communicates with the slightly diametricallyenlarged bore 25 which continues throughout the remaining length of theplunger.

An elongated groove 26 extends lengthwise of the plunger terminatingshort of the lower end thereof to provide a boss 28. A set screw 29 hasits inner end received in the groove 26 and permits reciprocation of theplunger within the outer sleeve while preventing separation of sametherefrom. The bore 24 and counterbores 22 and 23 as well as theexterior cylindrical surface 30 are machined within an overallconcentricity tolerance of about .002" T.I.R. thereby assuring a highdegree of accuracy in the maintenance of axial alignment conditions.

The seal assembly includes the body portion 32 which has an annulargroove 33 formed in its internal wall to receive the radially outwardlyprojecting annular fiange 34 of the insert 35. The insert includes theaxially extending hub portion 36 which has an inside diameter which isless than the outside diameter of the valve stem so as to provide a snugfit with the outside cylindrical surface 37 of the valve stem. Theinsert 35 may be formed of a synthetic resin material which is highlyresistant to wear, however, which is sufliciently flexible as to berather easily distorted by hand, such as when installing the fiangeportion 33 into the annular groove of the seal body 32.

The inside diameter 38 of the seal body beneath the insert is preferablyslightly greater (such as by about .010" to .020) than the insidediameter of the insert to facilitate the initial starting of the sealonto the end of the valve stem, as is best shown in FIGURE 3.

It will be noted that the upper end of the valve stem is provided with aseries of cylindrical lands 40, each having an outside diameter which iscommon with the outside diameter of the valve stem. Diametricallyreduced annular grooves 41 are formed between successive lands for usein conjunction with conventional valve springs of a conventionaloverhead type internal combustion engine. The significance of the landsMB is that the insert 35 must be driven over the successive landsWithout becoming dislodged from the seal body during the placement ofthe seal assembly into the final position as shown in FIGURE 2. The sealplacement tool adequately takes care of this problem.

Thus, in the use of the seal placement tool, the seal assembly isinitially manually started onto the end of the valve stem as shown inFIGURE 3 and then the sleeve 17 is guided over the valve stem until thecircular bore 20 is positioned onto the cylindrical shoulder 11 of thecylinder head casting. The inside diameter of bore 20 is only slightlylarger than the outside diameter of the cylinder head shoulder 11thereby accurately positioning the sleeve in a condition ofconcentricity with reference to the valve stem. The lowermost face 42-of the sleeve is flat and at right angles to the axis of the sleeve sothat when it is in engagement with the upper surface 16 of the cylindercasting, then accurate axial alignment of the sleeve and plunger withreference to the valve stem and guide is assured.

While holding the end face 42 of the sleeve against the surface of thecylinder head casting, the plunger 21 4.3 can then be promptly loweredrather rapidly (since concentricity and axial alignment is assured) andthe upper end of the seal body enters the first counterbore 23, the endface 44 thereof engaging the annular shoulder or inclined surface 45.The inside diameter of first counterbore 23 is sufficiently greater (byabout .005) than the outside diameter of the seal body at the upper endthereof so as to permit the upper end of the seal body to promptly entercounterbore 23 during the lowering of the plunger.

As the upper end of the valve stem enters bore 24, a further assuranceof concentricity and axial alignment is obtained as the plungercontinues downwardly during the placement of the seal assembly into thefinal position as shown in FIGURE 2. At the moment the seal assembly isplaced in final position, the lower end face 47 of the plunger engagesthe annular shoulder 19 to terminate downward movement of the plungerrelative to the sleeve.

The inside diameter of counterbore 22 is slightly larger (by about.010") than the inside diameter of counterbore 23 so as to permit thediametric expansion of the flange 314 of the seal as the locking ring isexpanded preparatory to the reception of same in the annular groove 13.

I have found that the placement of each seal assembly can be done veryrapidly without error and consequently without spoilage.

I claim:

1. For use in placing an elastic annular seal having axially spacedconcentric sealing surfaces in situs on a valve stem and on a hollowvalve stem guide, wherein the valve stem is reciprocable in the guideand projects beyond the end of the guide and wherein the guide ismounted in a cylinder head having a locating shoulder encircling theguide, a seal placement tool comprising:

(a) a sleeve having an end wall with a bore therethrough having aninside diameter slightly larger than the outside diameter of thelocating shoulder whereby the end wall encircles the shoulder;

(b) said sleeve having an internal bore concentric with the end wallbore;

(0) said end wall having an end face lying in a plane at right angles tothe axis of the sleeve end wall bore and sleeve internal bore;

(d) a plunger reciprocably mounted in the sleeve internal bore;

(e) said plunger having a bore with an inside diameter slightly greaterthan the outside diameter of the valve stem;

(if) said plunger having a first counterbore communicating with theplunger bore and a second counterbore communicating with the firstcounterbore;

(g) an annular shoulder formed at the junction of plunger bore and firstcounterbore for engaging the end of the seal.

2. A seal placement tool as set forth in claim 1 wherein the insidediameter of the'second counterbore in the plunger is greater than theoutside diameter of the seal to permit radial expansion of the sealduring placement on the valve stem and valve stem guide.

3. A seal placement tool as set forth in claim 2 wherein means on thesleeve and plunger interengage for preventing relative rotationtherebetween and for preventing separation of the plunger relative tothe sleeve.

4. For use in placing an elastic annular seal having axially spacedconcentric sealing surfaces in situs on a valve stem and on a hollowvalve stem guide, wherein the valve stem is reciprocable in the guideand projects beyond the end of the guide and wherein the guide ismounted in a cylinder head having a locating shoulder encircling theguide and a flat surface surrounding the shoulder and lying in a planeat right angles to the axis of the shoulder, a seal placement toolcomprising:

(a) a sleeve having. an end wall with a bore therethrough having aninside diameter slightly larger than the outside diameter of thelocating shoulder whereby the end wall encircles the shoulder;

(b) said sleeve having an internal bore concentric with the end wallbore;

(c) an annular shoulder formed at the base of the sleeve internal boreand lying in a plane at right angles to the axis thereof;

(d) said end wall having an end face lying in a plane at right angles tothe axis of the sleeve end wall bore and sleeve internal bore andengaging the flat surface on the cylinder head;

(e) a plunger reciprocably mounted in the sleeve internal bore andengaging the annular sleeve shoulder to terminate the placement of theseal;

(f) said plunger having a bore with an inside diameter slightly greaterthan the outside diameter of the valve stem;

(g) said plunger having a first counterbore communicating with theplunger bore and a second counterbore communicating with the firstcounterbore;

(h) an annular shoulder formed at the junction of plunger bore and firstcounterbore for engaging the end of the seal.

5. A seal placement tool as set forth in claim 4 wherein the insidediameter of the second counterbore in the plunger is greater than theoutside diameter of the seal to permit radial expansion of the sealduring placement on the valve stem and valve stem guide.

References Cited by the Examiner UNITED STATES PATENTS 1,393,605 10/1921Bergskaug 818.1 2,852,838 9/1958 Krutmeijer 29-275 WILLIAM FELDMAN,Primary Examiner.

I. C. PETERS, Assistant Examiner.

1. FOR USE IN PLACING AN ELASTIC ANNULAR SEAL HAVING AXIALLY SPACEDCONCENTRIC SEALING SURFACES IN SITUS ON A VALVE STEM AND ON A HOLLOWVALVE STEM GUIDE, WHEREIN THE VALVE STEM IS RECIPROCABLE IN THE GUIDEAND PROJECTS BEYOND THE END OF THE GUIDE AND WHEREIN THE GUIDE ISMOUNTED IN A CYLINDER HEAD HAVING A LOCATING SHOULDER ENCIRCLING THEGUIDE, A SEAL PLACEMENT TOOL COMPRISING: (A) A SLEEVE HAVING AN END WALLWITH A BORE THERETHROUGH HAVING AN INSIDE DIAMETER SLIGHTLY LARGER THANTHE OUTSIDE DIAMETER OF THE LOCATING SHOULDER WHEREBY THE END WALLENCIRCLES THE SHOULDER; (B) SAID SLEEVE HAVING AN INTERNAL BORECONCENTRIC WITH THE END WALL BORE; (C) SAID END WALL HAVING AN END FACELYING IN A PLANE AT RIGHT ANGLES TO THE AXIS OF THE SLEEVE END WALL BOREAND SLEEVE INTERNAL BORE; (D) A PLUNGER RECIPROCABLY MOUNTED IN THESLEEVE INTERNAL BORE; (E) SAID PLUNGER HAVING A BORE WITH AN INSIDEDIAMETER SLIGHTLY GREATER THAN THE OUTSIDE DIAMETER OF THE VALVE STEM;(F) SAID PLUNGER HAVING A FIRST COUNTERBORE COMMUNICATING WITH THEPLUNGER BORE AND A SECOND COUNTERBORE COMMUNICATING WITH THE FIRSTCOUNTERBORE; (G) AN ANNULAR SHOULDER FORMED AT THE JUNCTION OF PLUNGERBORE AND FIRST COUNTERBORE FOR ENGAGING THE END OF THE SEAL.